Combined gage and signal device.



v M. G. MELVIN.

COMBINED GAGE AND SIGNAL DEVICE.

APPLICATION FILED DEC. 3, 1907.

Patented Dec. 29, 1908.

' I B LAGK HANDLBS.

RlIIIIIIIIlIIlllIl/III UNITED STATES PATENT OFFICE.

\ MARK G. MELVIN, OF SORANTON, PENNSYLVANIA.

COMBINED GAGE AND SIGNAL DEVICE.

Specification of Letters Patent.

Patented Dec. '29, 1908.

Application filed December 3, 1907. Serial No. 404,950.

State of Pennsylvania, have invented new and useful Improvements in aCombined Gage and Signa Device, of which the followmg is aspeclfication.

This invention relates to-a gage of that type having separate Bourdontubes connected with a single source of pressure, one tube beingassociated with an indicating mechan sm for indicating the pressure of afluid 1n ounds or the level of a liquid in feet, an the other tube beingassociated with an electric switch for closing a circuit, including asignal when the pressure or level reaches an abnormally high or lowlimit. The invention has for one of its objects to improve and simplifythe construction and operation of apparatus'of this character so as tobe effective in service, simple and durable, and manufactured atcomparatively little expense.

A further object of the invention is the pIOYlSlOP of a combined gageand signaling device in which the operating parts are mounted in such amanner as to be removable with the Bourdon tubes and their support,while the parts are intact, thus facllltatlng the assembling of thevarious parts inthe manufacture of the instrument or the repair of theinstrument at any time.

tions.

Another object is to so .desi the instrument that the circuit-closingevice will be entirely housed within the same casing contaming theexpansible tubes and mechanisms connected therewith, the circuit-closingdeylce including adjustable contacts arranged lnslde the casing andsupported on the wall thereof, and cooperating with the contacts is amovable contact element or blade for com pletmg the circuit underabnormal condi- With these objects in view and others, as will appear asthe description proceeds, the lnventlon comprises the various novelfeatures of construction and arrangement of parts which will be morefully described ereinafter and set forth with particularity in theclalms appended hereto.

the accompanying drawing, which illustrates one of the embodiments ofthe mventlon, Figure 1 is a front view of the combined gage and si naldevice. .Fig. 2 is -tubes partially in section.

moved and showing one of the Bourdon Fig. 3 is a sectional view of thedevice. Fig. 4 is a fragmentary perspective view of parts of themechanism.

Similar reference characters are employed.

to designate corresponding parts throughout the several views.

The gage, in the presence instance, is designed for use as a pressureindicator whereby the pressure of a steam boiler or the like can beascertained at any time or as a level indicator for determining theheight of water or other liquid in a tank, and in connection therewithis employed a signal device which may include an electric alarm locatedin an engineers office or other remote point to give a warning when thepressure of the steam or the level of the water reaches a predeterminedhigh or low limit.

Referring to the drawing, A designates a dial including separate scales(1 and b which are divided respectively, into units for indicatingpressure in pounds and height in feet. A double-ended needle or hand Bis used in connection with both scales, the arm a of the needle beingblack or other appropriate color corresponding to the color of the scalea from which the indications are taken by the said arm. The arm I) islonger than the other arm so as to extend over the outer scale I), whichis red or other suitable color, to correspond with the said arm. Thearms extend in opposite directions and the zero marks ofthe scales aredisposed at diamet rically opposite points.

The dlal A is mounted in a casing C com posed of a cylindrical. shell 1,a glass front 2 secured in a ring 3 screwed on the shell, and a backplate 4 also rremovably secured in place by'screwing on the shell. Thedial A is fixed in the casing by screws 5 that pass through aperturesinthe dial and screw .lnto bosses 6 arranged on the shell of the casing,one of the bosses being shown at the top of Fi 2.

lVithiiithe casing is a base piece or sup- ;port 7 that'has a threadednipple 8 that extends through an opening 9 in the casing so as to beattached to a pipe and rising from the base pieceis a hollow head 10 towhich the lower ends of the symmetrically disposed Bourdon tubes 11 and12 are connected so that the same pressure will act upon both tubes withequal effect. The upper closed ends of the tubes are provided withdownwardly inclined arms 13 and 14 which cross each. other, the firstarm being connected with the movable. element of the circuit closer andthe second arm being connected with the needle actuating mechanism.Secured by screws 15 to the head 10 and rising from opposite sidesthereof are spaced standards 16 in which the arbor 17 is mounted, thesaid arbor extending through the dial for connection with the needle B.On the arbor 17 is a pinion 18 with which meshes a toothed sector 19carried by an oscillatory frame 20. The frame 20 swings on a rod 21supported in the lower extremities of the inclined arms 22 on thestandards 16. The frame 20 has an extension 23 to which is adjustablysecured the slotted member 24, the rod 21 passing through the slot 25 asshown in Fig. 4 so as to permit the member to be adjustedlongitudinally. The member is held in fixed position by a screw 26passing through the slot and screwing into the extension 23.

The tube 12 is connected by a link 27 with l the member 24 and the saidmember forms an adjustable connection between the tube andsector-carrying frame 20, whereby the adjustment of the needle withrespect to the scales can be accurately obtained. Projecting upwardlyand outwardly from the extensions 22 are extensions 28 that support across piece 29 and connected with the latter is the outer end 30 of ahair spring 31, the inner end of which is secured to the arbor 17 so asto return the needle to initial p'osltion.

The circuit closer for the signal-including circuit comprises a U-shapedframe 32 which is secured to the shell 1 by the screws or otherfastenings 33, the frame being insulated from the shell and screws byrubber, fiber or the like indicated at 34. The parallel arms 35 of theframe are apertured to receive the upper and lower adjustable contacts36 which are preferably screws so that they can be adjusted toward oraway from each other to vary the range of o eration. Movable between thecontacts 36 1s a blade or contact element 37 that is fulcrumed at 38 inline with the arbor 17, on a bracket 39. Between the arm 13 and element37 is a link 39 that has its upper ends hingedly connected with the saidarm and its lower end adjustably secured to the element by a slottedmember 40, which member is secured in position by screws 41 passingthrough the slot 42 of the member and screwing into the element. 'Bythis arrangement, the expansion of the tube 11 will cause the element 37to move toward and contact with the lower contact 36 and thereby closethe alarm includin circuit when the pressure or level of the uid becomesabnormally high. The contraction of the tube causes a reverse movementso that the circuit will be closed by the element 37 engaging the uppercontact as shown in Fig.

4 pressure or level.

eoaecc 2 under abnormally low conditions as to The frame 32 iselectrically connected with the binding post 43 by a conductor 44, andthe casing is electrically connected with the binding post 45, so thatthe circuit is completed through the binding post 45, casing C, basepiece 7, standard 16, racket 39, element 37, one of the contacts 36,frame 32, conductor 44, and other bindin%post 43.

y providing separate Bourdon tubes for the purpose of actuating theindicating needle and the circuit closer, the needle can continue tomove after the circuit-closing switch is entirely closed by the othertube, so that the exact condition as to ressure or height of liquid inthe system wit which the apparatus is used can be ascertained from theneedle, should the alarm device fail to operate for any reason. As theworking parts are all carried by the base piece 7, they can be readilyremoved from the casing without disassembling the parts, it beingnecessary to remove screws 46 and either the front or the base of thecasing to permit the internal mechanism to be lifted out. lit will thusbe'seen that inspection or repair of the mechanism can be easily andquickly accomplished.

- The contacts 36 are preferably tipped with platinum, as indicated at36' and the element "37 has pieces 37 of platinum arranged incooperative relation with the platinum tipped contacts 36,'so that the sarking when the alarm circuit is broken not destroy the parts.

In order to prevent damage to the instru ment from accidental passagetherethrough of current in case of grounding of the instrument when thelatter is used in an electric power house, a binding post 48 is providedon the casingof the instrument and a grounded wire 49 may be connectedtherewith so as to admit of a high voltage current to be carried 0Ewithout causing damage.

From the foregoing description, taken in connection with theaccompanying drawing, the advantages of the construction and .of themethod of 0 eration will be readily a parent to those s rilled in theart to which t e invention appertains, and While I have de scribed theprinciple of operation of the invention, together with the apparatuswh1ch I now consider to be the best embodiment thereof, I desire to haveit understood that the a paratus shown is merely illustrative and t atsuch changes may be made when desired as are within the scope of theclaims.

Having thus described the invention, what I claim is 1. In an apparatusof the class described, the combination of a/casing, binding postsmounted on the casing, a pressure responsive tube a base supporting thetube and provided with means exterior to the casing for eoasooconnection with a pipe, a fulcrumed contact member, a link connectingthe free end of the tube with the member, an insulated support arrangedwithin the casing and supported on the latter and provided withapertured extremities, adjustable contacts mounted in the apertures ofthe extremities and disposed at opposite sides of the free end of thecontact member for engagement therewith, in combination with anindicating mechanism. 2. In an apparatus of the class described, thecombination of a casing, a pressure-actuated tube, 'means for mountingthe tube in the casing, a fulcrumed contact element in the casing, alink hingedly connected with the free end of the tube, a memberadjnstably secured to one end of the element, a hinged connectionbetween the member and link, a supporting member within the casing andinsulated therefrom,'and alining screws on the supporting member andarranged with their inner ends spaced apart at opposite sides of thefree end of the said element.

3. The combination of a pressure gage casing, an element movable inresponse to variations in pressure and mounted within the casing, asupport arranged within the casing and insulated therefrom, means forsecuring the support in fixed position, adjustable contacts mounted onthe support and electrically connected therewith and disposed atopposite sides of the said element for contact therewith duringabnormally high or low pressure, binding posts for connection with asignal circuit, means for electrically connecting one binding post withthe said element, a

connection within the casingfor electrically connecting the other postwith the said support, and means for insulating one post from the other.

4. In an apparatus of the class described, the combination of a casing,a base piece removably secured therein, a flexible tube connected withthe base piece, standards mountand insulated from the casing, adjustablecontacts on the support and arranged to e engaged by the element, abinding post electrically connected with the support and insulated fromthe casing, and a binding post electrically connected with the casing.

In testimony whereof I affix my signature in presence of two witnesses.

MARK G. MELVIN.

Witnesses J osEPH'F. GILROY, PATRICK O. GILMARTIN.

